Is a Juice Cleanse Good For You?

A detoxed system! A flatter stomach! These are just a couple of the big benefits that supposedly come with cleanses. Find out if they really deliver.

After a particularly indulgent week (or season or year), the idea of doing a cleanse might seem appealing: Consume nothing but juices for a few days and—presto!—you’re healthier. According to the companies that sell cleansing drinks, their regimens can help you fit into your jeans, boost your mental clarity, improve the state of your skin, regulate digestion, and, most important, remove toxins from your system—which is the key, go the claims, to well-being.

Toxins, Explained

Every day, we take in chemicals from our food (like colorants and preservatives), water (like chlorine), and air (like carbon monoxide). “Toxins can build up in the body, causing inflammation and a weakened immune system,” says Susan Blum, M.D., the founder and director of the Blum Center for Health, an integrative medical facility in Rye Brook, New York. “This may make us more susceptible to chronic illness, such as headaches, arthritis, and asthma, not to mention heart disease and cancer.” Our liver, kidneys, and colon are designed to filter and expel waste and toxins, but cleanse enthusiasts believe the hazards of modern life are too much for these organs to handle completely.

The Theory Behind Cleanses

It’s pretty simple: You replace all meals and snacks with juices made from (preferably organic) fruits and vegetables for about three to seven days. The idea is that when our bodies are freed from the burden of digesting solid food, they can more efficiently release the toxins swimming in our system. But while experts agree that juices contain many nutrients, “a special three-day cleanse won’t magically improve your body’s natural waste-removal system,” says Christine L. Frissora, a gastroenterologist at New York–Presbyterian/Weill Cornell Medical Center, in New York City. In fact, “we cleanse all the time if we eat properly, because that enables our bodies to function optimally,” says Joel Fuhrman, a family physician in Flemington, New Jersey, and the author of Eat to Live ($16, amazon.com).

What About Weight Loss?

You are likely to lose weight if you go on a cleansing regimen. “However, most of it is water weight,” says Marissa Lippert, a registered dietitian in New York City. When you eat whole foods, especially carbohydrates such as breads and grains, your body needs to hold on to water to digest them properly. Take away the food and the water disappears, too, which can translate to a drop on the scale. The problem: When you begin eating solids again, the water may come right back, leaving you where you started. What’s more, for some people, the restrictive nature of a cleanse can cause carbohydrate and sugar cravings, “making it easy to spiral back into not-so-great eating habits once you complete it,” says Lippert.

Possible Pitfalls

For most people, a short-term cleanse isn’t dangerous; it just might make you tired and headachy (and hungry). But experts don’t recommend cleanses for those who have certain medical conditions or are taking some prescription drugs. “Patients on medication to control blood pressure could faint if their blood pressure drops too low while on a cleanse,” says Fuhrman. People on blood-sugar or diabetes medication could feel dizzy or faint, says Lippert. And it goes without saying that cleanses are off-limits to children and to women who are pregnant or breast-feeding.

The Bottom Line

“For good health, we need to not only reduce our exposure to toxins but also supply the body with the nutrients it requires,” says Blum. It’s fine if you want to jump on the juice bandwagon: Juices can be an easy way to get in your greens, for instance, without having to eat fistfuls of kale (see Healthy Green Juice recipe). But juices should be just one part of a balanced diet that includes minimally processed foods, good-quality lean protein, and plenty of whole fruits and vegetables—which, ironically, are the real cleansers. “They act like a scrub brush for your digestive tract,” says Lippert. And while a cleanse could feel like a psychological jump-start to healthy eating, it’s not the solution for long-term wellness. Simply put, “being healthy is a lifestyle,” says Ann Louise Gittleman, Ph.D., a certified nutrition specialist in Post Falls, Idaho, and the author of The Fat Flush Plan ($25, amazon.com). “It’s not a one-time, three-day event.”